Karl Kashofer

Copy Number Profiling Implicates Thin High-Grade Squamous Intraepithelial Lesions as a True Precursor of Cervical Human Papillomavirus-Induced Squamous Cell Cancer

Full-thickness high-grade squamous intraepithelial lesions (HSIL) are precursors of invasive cervical squamous cell carcinoma (SCC). The World Health Organization and Lower Anogenital Squamous Terminology Standardization Project for human papilloma virus (HPV)-associated lesions divide full-thickness HSIL of the cervix into thin HSIL with thickness of 1 to 9 cell layers and the typical full-thickness HSIL of >10 cell layers. Although HPV oncogene transcripts and p16ink4a overexpression, as markers of transforming HPV infection, are detectable in thin HSIL, the biological significance of thin HSIL in cervical carcinogenesis remains poorly understood. To further characterize thin HSIL, we performed a comparative study of chromosomal copy number variations (CNV), an analysis of dysregulated genes present in the segments with CNV, and a generalized genetic complexity calculation for 31 thin HSIL, 31 thick HSIL, 24 microinvasive SCC (pT1a SCC), and 22 highly invasive SCC samples. Thin HSIL share various CNV and specific dysregulated gene pathways with thick HSIL and invasive SCC. Thin HSIL exhibited an average CNV of 11.6% compared with 14.1% for thick HSIL, 15.5% for pT1a SCC, and 26.6% for highly invasive SCC. The CNV included gains at 1q and 3q (40% and 43%, respectively), partial loss of 3p, and loss of chromosomes 11 (18%), 16 (50%), 20 (35%), and 22 (40%). Pathways affected solely in thin HSIL were those enhancing immune evasion and primarily involved the (interleukin) IL6, IL21, and IL23 genes. ILs are transiently upregulated in response to infection and play a crucial role in mounting antitumor T-cell activity. Deregulation reflects an attempt by the HPV to evade the initial immune response of the host. The primary pathways shared by thick HSIL and invasive SCC were interactions between lymphoid and nonlymphoid cells, NOTCH2 signaling, tight junction interactions (primarily of the claudin family), and FGR2 alternative splicing. Our results show that thin HSIL carry similar genetic changes as thick HSIL and SCC, indicating that thin HSIL are true precursor lesions that can progress to thick HSIL and SCC.

Robust Assessment of Homologous Recombination Deficiency Genomic Instability by OncoScan Microarrays

Genomic instability scars are markers for detecting homologous recombination deficiency (HRD) status in patients with ovarian cancer and predicting the response to poly (ADP-ribose) polymerase inhibitor treatment. Currently, only a few reliable and validated assays are available, with the Myriad myChoice CDx being the most commonly used commercial assay for genomic instability scar score determination. Given the need for a more straightforward, accessible, and reliable method for detecting genomic instability scars methods, in this work, we describe the feasibility of using the microarray OncoScan copy number variant assay and open-source software packages to quantify genomic instability scores, and the development of an open-access online platform for genomic instability score calculation. The laboratory-developed test accurately classified homologous recombination-proficient and recombination-deficient samples based on genomic instability scores derived from the OncoScan copy number variant assay. Internally evaluated genomic instability scores demonstrated a 92% overall agreement and a higher sample success rate compared with externally analyzed genomic instability scar scores. The availability of HRD determination has doubled the number of patients eligible for poly (ADP-ribose) polymerase therapy. The assay can be conveniently performed on individual samples, and the open-access online platform facilitates HRD determination without the need for specialized bioinformatics support.